Aviva Hit by Subsidence Claims Surge After Record Hot Summer

Aviva rode a brutal stretch of subsidence claims through a July-to-September window it calls a peak subsidence period, chief executive Amanda Blanc told Bloomberg, with claims still arriving into October. The UK's largest insurer won't say how big the jump was. Subsidence repairs usually mean cracked walls, sloping floors and doors and windows that no longer sit straight.

Aviva isn't alone. Hastings Direct said it took record subsidence claims in August, up 140% on a year earlier, while Axa — one of the country's biggest home insurers — called it a surge year for subsidence. The pattern follows two record hot summers in the UK, and August this year came in as the joint hottest month ever recorded globally.

The money has ballooned too. The average UK subsidence claim hit £20,000 between April and June, more than £2,000 above the same period a year earlier, according to the Association of British Insurers. Insurers paid out £72m on domestic subsidence claims, up from £60m a year before. Dry summers shrink the ground under a house, then wet winters make it swell again — wrecking foundations from below.

The problem has a long tail. The British Geological Survey reckons up to 11% of UK homes — more than 4.2m — could be at risk by 2070. Older properties with shallow foundations on clay-rich soil face the biggest threat, with London, Essex, Kent and the area around Oxford among the most exposed.

Blanc's advice to homeowners: watch the drains, pipes and gutters, and patch leaks before they soak the ground under the house. It's about managing trees and plumbing, she said. Even so, she painted Aviva as thriving — general insurance premiums rose 19% in the third quarter, reaching £11.8bn. Aviva is in great shape, she said, calling the first nine months of 2026 excellent and pointing to growth in general insurance and wealth.